RFR(M): 8233787: Break cycle in vm_version* includes

[Schmidt, Lutz]

Oh, oh,
looks like I stepped into a beehive... Found JDK-8202579 and JDK-8145956 talking about the unwanted use of Abstract_VM_Version.

My intended change would not tackle that "mess", as you call it. But it would make potential future cleanups a little bit easier by ensuring all of hotspot code only includes vm_version.hpp. I'm in the process of modifying my initial change to reflect Kim's suggestions. I'll send it out Tuesday (hopefully), Wednesday the latest. 

Regards,
Lutz

On 11.11.19, 11:54, "David Holmes" <david.holmes at oracle.com> wrote:

    Also note we have an open RFE to try and fix the VM_Version vs 
    Abstract_VM_version mess. But it's such a mess it keeps getting deferred.
    
    David
    
    On 9/11/2019 11:58 am, Kim Barrett wrote:
    >> On Nov 7, 2019, at 10:59 AM, Schmidt, Lutz <lutz.schmidt at sap.com> wrote:
    >>
    >> Dear all,
    >>
    >> may I please request reviews for this cleanup? It's a lot of files with just some #include statement changes. That makes the review process tedious and not very challenging intellectually.
    >>
    >> Anyway, your effort is very much appreciated!
    >>
    >> jdk/submit results pending.
    >>
    >> Bug:    https://bugs.openjdk.java.net/browse/JDK-8233787
    >> Webrev: http://cr.openjdk.java.net/~lucy/webrevs/8233787.00/
    >>
    >> Thank you!
    >> Lutz
    > 
    > I don't think this is the right approach.  It makes all the
    > vm_version_<cpu>.hpp files not be stand alone, which I think is not a
    > good idea.
    > 
    > I thik the real problem is that Abstract_VM_Version is declared in
    > vm_version.hpp.  I think that file should be split into
    > abstract_vm_version.hpp (with most of what's currently in
    > vm_version.hpp), with vm_version.hpp being just (untested)
    > 
    > <code>
    > #ifndef SHARE_RUNTIME_VM_VERSION_HPP
    > #define SHARE_RUNTIME_VM_VERSION_HPP
    > 
    > #include "utilities/macros.hpp"
    > #include CPU_HEADER(vm_version)
    > 
    > #endif // SHARE_RUNTIME_VM_VERSION_HPP
    > </code>
    > 
    > Change all the vm_version_<cpu>.hpp files #include
    > abstract_vm_version.hpp rather than vm_version.hpp.
    > 
    > Other than in vm_version_<cpu>.hpp files, always #include
    > vm_version.hpp.
    >